1. Field
The present disclosure relates to a vehicle active damper that actively suppresses vibrations occurring in the body of a vehicle, soon as a car.
2. Description of the Related Art
In a vehicle installed with a reciprocating engine, such as a car, a radiator is provided for cooling a liquid medium employed as reciprocating engine coolant. The radiator, which is a weighty object, is generally attached to a front section of the vehicle so as to readily catch the flow of air accompanying vehicle travel. Japanese Unexamined Patent Application Publication No. 57-084223 describes a vibration absorbing device that absorbs vibrations occurring in a vehicle body by configuring a dynamic damper. The dynamic damper is configured by attaching a radiator to the vehicle body using an elastic body, such as rubber, and employing the radiator as an inertial mass.
The vibration absorbing device according to the Japanese Unexamined Patent Application Publication No. 57-084223 enables vibration occurring in the vehicle body to be absorbed due to the manifestation of a dynamic damper function.
However, in the vibration absorbing device according to the Japanese Unexamined Patent Application Publication No. 57-084223, the natural vibration frequency of the dynamic damper configured by interposing the elastic body, such as rubber, between the radiator and the vehicle body is set to fixed values (for example, 20 Hz to 30 Hz) by parameters of the modulus of elasticity of the elastic body and the mass of the radiator. If is therefore not possible to absorb the vibration components of frequency bands outside of the fixed values.
Moreover, if the modulus of elasticity of the elastic body, such as rubber, changes due to heat radiated from the radiator as it becomes hot, then the natural vibration frequency of the dynamic damper also changes. There is accordingly a concern that, as a result, it may not foe possible for a sufficient damping effect to be manifested for vibration components in the target frequency band.